This invention relates to a novel process for the preparation of cyclic ethers. More particularly, the invention is concerned with a process for effecting a cyclizing dehydration of alkanedoils in which the hydroxyl groups are separated by a chain of at least 4 carbon atoms, to form cyclic ethers which can be five, six and higher membered rings, e.g., tetrahydrofuran, tetrahydropyran, etc. The process is carried out in the presence of highly active palladium salt containing catalysts, thereby providing a practical and economical process adapted to operation on a technical scale for the conversion of diol compounds to cyclic ethers.